/*
 * qrencode - QR Code encoder
 *
 * Input data splitter.
 * Copyright (C) 2006-2011 Kentaro Fukuchi <kentaro@fukuchi.org>
 *
 * The following data / specifications are taken from
 * "Two dimensional symbol -- QR-code -- Basic Specification" (JIS X0510:2004)
 *  or
 * "Automatic identification and data capture techniques --
 *  QR Code 2005 bar code symbology specification" (ISO/IEC 18004:2006)
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
 */

#include "config.h"
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include "qrencode.h"
#include "qrinput.h"
#include "qrspec.h"
#include "split.h"

#define isdigit(__c__) ((unsigned char)((signed char)(__c__) - '0') < 10)
#define isalnum(__c__) (QRinput_lookAnTable(__c__) >= 0)

#if !HAVE_STRDUP
#undef strdup
char* strdup(const char* s)
{
    size_t len = strlen(s) + 1;
    void* new = malloc(len);

    if (new == NULL)
        return NULL;

    return (char*)memcpy(new, s, len);
}
#endif

static QRencodeMode Split_identifyMode(const char* string, QRencodeMode hint)
{
    unsigned char c, d;
    unsigned int word;

    c = string[0];

    if (c == '\0')
        return QR_MODE_NUL;

    if (isdigit(c))
    {
        return QR_MODE_NUM;
    }
    else if (isalnum(c))
    {
        return QR_MODE_AN;
    }
    else if (hint == QR_MODE_KANJI)
    {
        d = string[1];

        if (d != '\0')
        {
            word = ((unsigned int)c << 8) | d;

            if ((word >= 0x8140 && word <= 0x9ffc) || (word >= 0xe040 && word <= 0xebbf))
            {
                return QR_MODE_KANJI;
            }
        }
    }

    return QR_MODE_8;
}

static int Split_eatNum(const char* string, QRinput* input, QRencodeMode hint);
static int Split_eatAn(const char* string, QRinput* input, QRencodeMode hint);
static int Split_eat8(const char* string, QRinput* input, QRencodeMode hint);
static int Split_eatKanji(const char* string, QRinput* input, QRencodeMode hint);

static int Split_eatNum(const char* string, QRinput* input, QRencodeMode hint)
{
    const char* p;
    int ret;
    int run;
    int dif;
    int ln;
    QRencodeMode mode;

    ln = QRspec_lengthIndicator(QR_MODE_NUM, input->version);

    p = string;

    while (isdigit(*p))
    {
        p++;
    }

    run = p - string;
    mode = Split_identifyMode(p, hint);

    if (mode == QR_MODE_8)
    {
        dif = QRinput_estimateBitsModeNum(run) + 4 + ln
              + QRinput_estimateBitsMode8(1) /* + 4 + l8 */
              - QRinput_estimateBitsMode8(run + 1) /* - 4 - l8 */;

        if (dif > 0)
        {
            return Split_eat8(string, input, hint);
        }
    }

    if (mode == QR_MODE_AN)
    {
        dif = QRinput_estimateBitsModeNum(run) + 4 + ln
              + QRinput_estimateBitsModeAn(1) /* + 4 + la */
              - QRinput_estimateBitsModeAn(run + 1) /* - 4 - la */;

        if (dif > 0)
        {
            return Split_eatAn(string, input, hint);
        }
    }

    ret = QRinput_append(input, QR_MODE_NUM, run, (unsigned char*)string);

    if (ret < 0)
        return -1;

    return run;
}

static int Split_eatAn(const char* string, QRinput* input, QRencodeMode hint)
{
    const char* p, *q;
    int ret;
    int run;
    int dif;
    int la, ln;

    la = QRspec_lengthIndicator(QR_MODE_AN, input->version);
    ln = QRspec_lengthIndicator(QR_MODE_NUM, input->version);

    p = string;

    while (isalnum(*p))
    {
        if (isdigit(*p))
        {
            q = p;

            while (isdigit(*q))
            {
                q++;
            }

            dif = QRinput_estimateBitsModeAn(p - string) /* + 4 + la */
                  + QRinput_estimateBitsModeNum(q - p) + 4 + ln
                  + (isalnum(*q) ? (4 + ln) : 0)
                  - QRinput_estimateBitsModeAn(q - string) /* - 4 - la */;

            if (dif < 0)
            {
                break;
            }
            else
            {
                p = q;
            }
        }
        else
        {
            p++;
        }
    }

    run = p - string;

    if (*p && !isalnum(*p))
    {
        dif = QRinput_estimateBitsModeAn(run) + 4 + la
              + QRinput_estimateBitsMode8(1) /* + 4 + l8 */
              - QRinput_estimateBitsMode8(run + 1) /* - 4 - l8 */;

        if (dif > 0)
        {
            return Split_eat8(string, input, hint);
        }
    }

    ret = QRinput_append(input, QR_MODE_AN, run, (unsigned char*)string);

    if (ret < 0)
        return -1;

    return run;
}

static int Split_eatKanji(const char* string, QRinput* input, QRencodeMode hint)
{
    const char* p;
    int ret;
    int run;

    p = string;

    while (Split_identifyMode(p, hint) == QR_MODE_KANJI)
    {
        p += 2;
    }

    run = p - string;
    ret = QRinput_append(input, QR_MODE_KANJI, run, (unsigned char*)string);

    if (ret < 0)
        return -1;

    return run;
}

static int Split_eat8(const char* string, QRinput* input, QRencodeMode hint)
{
    const char* p, *q;
    QRencodeMode mode;
    int ret;
    int run;
    int dif;
    int la, ln, l8;
    int swcost;

    la = QRspec_lengthIndicator(QR_MODE_AN, input->version);
    ln = QRspec_lengthIndicator(QR_MODE_NUM, input->version);
    l8 = QRspec_lengthIndicator(QR_MODE_8, input->version);

    p = string + 1;

    while (*p != '\0')
    {
        mode = Split_identifyMode(p, hint);

        if (mode == QR_MODE_KANJI)
        {
            break;
        }

        if (mode == QR_MODE_NUM)
        {
            q = p;

            while (isdigit(*q))
            {
                q++;
            }

            if (Split_identifyMode(q, hint) == QR_MODE_8)
            {
                swcost = 4 + l8;
            }
            else
            {
                swcost = 0;
            }

            dif = QRinput_estimateBitsMode8(p - string) /* + 4 + l8 */
                  + QRinput_estimateBitsModeNum(q - p) + 4 + ln
                  + swcost
                  - QRinput_estimateBitsMode8(q - string) /* - 4 - l8 */;

            if (dif < 0)
            {
                break;
            }
            else
            {
                p = q;
            }
        }
        else if (mode == QR_MODE_AN)
        {
            q = p;

            while (isalnum(*q))
            {
                q++;
            }

            if (Split_identifyMode(q, hint) == QR_MODE_8)
            {
                swcost = 4 + l8;
            }
            else
            {
                swcost = 0;
            }

            dif = QRinput_estimateBitsMode8(p - string) /* + 4 + l8 */
                  + QRinput_estimateBitsModeAn(q - p) + 4 + la
                  + swcost
                  - QRinput_estimateBitsMode8(q - string) /* - 4 - l8 */;

            if (dif < 0)
            {
                break;
            }
            else
            {
                p = q;
            }
        }
        else
        {
            p++;
        }
    }

    run = p - string;
    ret = QRinput_append(input, QR_MODE_8, run, (unsigned char*)string);

    if (ret < 0)
        return -1;

    return run;
}

static int Split_splitString(const char* string, QRinput* input,
                             QRencodeMode hint)
{
    int length;
    QRencodeMode mode;

    if (*string == '\0')
        return 0;

    mode = Split_identifyMode(string, hint);

    if (mode == QR_MODE_NUM)
    {
        length = Split_eatNum(string, input, hint);
    }
    else if (mode == QR_MODE_AN)
    {
        length = Split_eatAn(string, input, hint);
    }
    else if (mode == QR_MODE_KANJI && hint == QR_MODE_KANJI)
    {
        length = Split_eatKanji(string, input, hint);
    }
    else
    {
        length = Split_eat8(string, input, hint);
    }

    if (length == 0)
        return 0;

    if (length < 0)
        return -1;

    return Split_splitString(&string[length], input, hint);
}

static char* dupAndToUpper(const char* str, QRencodeMode hint)
{
    char* newstr, *p;
    QRencodeMode mode;

    newstr = strdup(str);

    if (newstr == NULL)
        return NULL;

    p = newstr;

    while (*p != '\0')
    {
        mode = Split_identifyMode(p, hint);

        if (mode == QR_MODE_KANJI)
        {
            p += 2;
        }
        else
        {
            if (*p >= 'a' && *p <= 'z')
            {
                *p = (char)((int) * p - 32);
            }

            p++;
        }
    }

    return newstr;
}

int Split_splitStringToQRinput(const char* string, QRinput* input,
                               QRencodeMode hint, int casesensitive)
{
    char* newstr;
    int ret;

    if (string == NULL || *string == '\0')
    {
        errno = EINVAL;
        return -1;
    }

    if (!casesensitive)
    {
        newstr = dupAndToUpper(string, hint);

        if (newstr == NULL)
            return -1;

        ret = Split_splitString(newstr, input, hint);
        free(newstr);
    }
    else
    {
        ret = Split_splitString(string, input, hint);
    }

    return ret;
}
